docstr: Number of classes for each node.
docstr_tok: ["Number","of","classes","for","each","node","."]
code: def num_classes(self):
      r"""Number of classes for each node."""
      return 2
  
file_path: dgl/examples/pytorch/evolveGCN/dataset.py
imports: import os
  import dgl
  import numpy
  import pandas
  import torch
label_desc: Use image node_id 3 for calling the EllipticDataset obj's underlying member method code with example usage: obj.num_classes() and returns: int